EP2316416B1 - Skin-lightening cosmetic compound - Google Patents

Description

The invention relates to a skin lightening cosmetic composition, a cosmetic method and a skin lightening set.

Koji acid and arbutin have long been known as cosmetic brighteners, for which extensive test results have been published. The shortcomings found such as instability, side effects due to skin irritations, inadequate efficacy have meant that the efficacy should be improved with the help of various plant extracts. In the EP 2092837 it is found that problems also occurred with regard to stability and color changes. Although the addition of vitamin C also showed improvement effects for the skin lightening, but did not have sufficient stability.

Pure plant extracts like the one in WO 2009/069839 described Magnolia sieboldii extract showed only after 8 weeks according to desirable whitening effects.

The WO 2009/105294 describes a variety of known skin whiteners, all of which are said to be in "association structures", ie embedded in liposomal, lamellar or liquid crystalline structures. The results achieved are not reported except for a Sting test.

The EP 1 640 041 A1 relates to a cosmetic whitening and cleansing composition for the skin containing extracts of lotus, kiwi, licorice and orchids. In the WO 2008/152159 A2 describes the cosmetic use of 6-hydroxy-7-methoxy-2,2-dimethylchroman and related substances together with a variety of other skin lightening substances or plant extracts. The JP 2009-137846 describes skin whitening effects of leaf extracts of Rutaceae citrus group. CN 2002-189009 relates to a cosmetic agent which is also said to cause skin whitening, consisting of ruby, jade and medicinal stone powder of 1 nm to 10 mm grain size, wherein the jade content is 30%. in the SÖFW Journal 134, 7-2008, pp. 53-57 the skin lightening effect of Chromabright® is described.

Another object is to provide a cosmetic skin lightening process utilizing various cosmetic composition applications.

A further object is to provide a kit, with its individual application forms of the composition a quick and permanent lightening effect of dark skin or dark spots on fair skin can be achieved.

According to the invention, a skin-lightening cosmetic composition comprises cosmetic auxiliaries and a combinatorial unit consisting of ground white jade stone with an average particle size D ₅₀ of 5-1 μm, arbutin, a lotus flower extract, a kumquat fruit extract and dimethylmethoxy chroman palmitate.

Here, the concentration of the ground white jade stone is in the range of 0.01 to 0.5% by weight, of the arbutin in the range of 0.1 to 1.0% by weight, of the lotus flower extract in the range of 0.5 to 1 , 5% by weight, of the kumquat fruit extract in the range of 0.1 to 2.5% by weight and of the dimethylmethoxy chroman palmitate in the range of 0.01 to 0.1% by weight, in each case based on the total weight the cosmetic composition.

1. (a) ein wesentlicher Betrag der Hautaufhellung bereits nach sehr kurzer Anwendungszeit auftritt, z.B. nach 7 - 10 Tagen,
2. (b) der Aufhellungseffekt sehr lange anhält, z.B. nach 3-wöchiger Behandlung für einen weiteren Zeitraum von wenigstens 3 Wochen
3. (c) weder im Behandlungszeitraum noch danach merkliche Hautirritationen auftreten
4. (d) keine unerwünschten Farbtonänderungen im Behandlungszeitraum und danach auftreten.

It has surprisingly been found that the combinatorial unit according to the invention not only exhibits the expected brightening effect for the skin, but also that

1. (a) a substantial amount of skin lightening already occurs after a very short application time, eg after 7 to 10 days,
2. (b) the lightening effect lasts for a very long time, eg after 3 weeks of treatment for a further period of at least 3 weeks
3. (c) no noticeable skin irritations occur during the treatment period or thereafter
4. (d) no unwanted color changes occur during and after the treatment period.

By "combinatorial unit" is meant the mixture of the above-mentioned components which are present in their unencapsulated form; not incorporated in liposomes or lamellar or similar structures, and which is preferably incorporated into the cosmetic composition as a separately prepared mixture.

The interaction mechanism of the 5 components has not yet been elucidated. A special feature is that it is a combination of water-soluble ingredients (arbutin and plant extracts), oil-soluble ingredients (chroman palmitate) and insoluble particles (jade). Without being bound to any theory, the variety of compounds in the kumquat fruit extract could also play a special role, particularly as regards the stability of the whole product and its very rapid activity. Another special feature is that all 5 ingredients are in free form, so unencapsulated.

The composition of the invention contains inter alia a ground white jade stone. "White" in the sense of the invention is a range from pure white to a light green and covers the colors of the RAL table white-green (RAL 6019), light green (RAL 6027), pastel turquoise (RAL 6034), semi-gloss white (RAL 8020), cream white (RAL 9001), off-white (RAL 9002) and signal white (RAL 9013). "RAL" is a registered trademark of RAL gemeinnützigen GmbH of the RAL Deutsches Institut für Gütesicherung und Kennzeichnung e.V. in Sankt Augustin, Germany.

"Particle size D ₅₀ " means a Gaussian distribution curve of the particles in which at least 50% of the particles are in the range 5-10 μm and the remainder above and below this range. However, the powder contains no particles> 40 microns, wherein the proportion of particles in the range of 30 to 40 microns is less than 3%.

Preferred proportions of the jade powder are in the range of 0.05 to 0.5 wt .-%, in particular 0.08 to 0.2 wt .-%.

Although the known under the trade and INCI name arbutin hydroquinone D-glucose (α-arbutin) has known skin lightening effects, however, according to the manufacturer, even at concentrations of 2 wt .-% noticeable only after about 3 months at e.g. Liver spots. However, the effect at reduced concentrations of preferably 0.1-0.8% by weight, especially 0.2-0.6% by weight, is surprisingly rapid along with the other ingredients and the stability of the arbutin is significantly longer as was to be expected.

The lotus flower extract in the combinatorial unit is an extract obtained at 12 to 30 ° C with a polyhydric alcohol such as propylene glycol. Preferred proportions of the extract are in the range of 0.6 to 1.3 wt .-%, in particular 0.8 to 1.2 wt .-%. A commercial product is e.g. Hydroglycolic Extract of Lotus Flowers Decolorized by Greentech, Saint Beauzire, France.

According to the invention, a kumquat extract is also used. Kumquat with the Latin name Fortunella crassifolia, F. hindsii, F. japonica (Syn. Citrus japonica), F. margarita, F. obovata, belongs to the family of the rhodial family and forms plum-shaped fruits. The extract of the fruits with peel is mixed with a polyhydric alcohol, e.g. Propylene glycol recovered at 12 to 35 ° C. A commercial extract is e.g. Citrus Japonica Fruit Extract (INCI), named Kumquat Hydroglycolic Extract by Greentech, Saint Beauzire, France.

Dimethylmethoxy Chroman palmitate (proposed INCI name) is a white powdery solid with tyrosinase activity-inhibiting activity from Lipotec, Gavà-Barcelona, Spain (Chromabright).

The composition according to the invention comprises further cosmetic adjuvants such as sunscreen filters, antioxidants, hyaluronic acid, gelling agents, emulsifiers, cosmetic ethers, cosmetic esters, oils, clay minerals and mixtures thereof as well as water, preservatives, perfumes, color pigments, humectants, other plant extracts such as chamomile extract, thickening agents, α- hydroxy acids, Peptides, flavonoids, gelling agents, polyhydric and monohydric alcohols and silicates.

The sunscreen filters include UVA filters, UVB filters and broadband filters, which may be of generally organic or inorganic origin. Particularly preferred for the present invention are organic UVA and UVB filters, such as diethylamino hydroxybenzoyl hexyl benzoates, benzophenone-3, benzophenone-4, ethylhexyl methoxycinnamate, ethylhexyl triazone, octocrylene, benzophenone-9, PABA, homosalates, phenylbenzimidazole sulfonic acid, Terephthalidene Dicamphor Sulfonic Acid, Butyl Methoxydibenzoylmethane, Benzophenone-5 (sodium salt), Ethylhexyl Dimethyl PABA, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazines and mixtures thereof.

The quantities used are chosen by a person skilled in the art in order to achieve sun protection factors (SPF or SPF) in the range from 8 to 30, preferably 10 to 20, and to ensure balanced protection against UVA and UVB rays.

As antioxidants, vitamins such as vitamin A, vitamin C and / or vitamin E and their derivatives such as palmitates, phosphates, acetates are used. Other antioxidants are carotene and carotenoids, amino acids, α-hydroxy acids, uric acid, etc.

Preferred gelling agents are e.g. Carbomer, guar gum, xanthan gum, alginates, polyvinyl alcohol, polyvinylpyrrolidone. Particularly preferred is carbomer.

The emulsifiers used are surface-active agents which ensure a stable O / W or W / O emulsion, in particular an oil-in-water emulsion (O / W). The proportion of the surface-active agent is usually in the range of 0.01 to 20 wt .-%, preferably 0.1 to 5 wt .-%. Known nonionic emulsifiers include those of the steareth-2 to steareth-1 00 series formed from stearyl alcohol and various ethylene oxide units of 2-100; Beheneth-5 to beheneth-30 formed from behenyl alcohol and 5-30 ethylene oxide units; Ceteareth 2-100, formed from stearyl and cetyl alcohol with 2-100 ethylene oxide units; Ceteth 1-45, formed from cetyl alcohol and 1-45 ethylene oxide units, etc. Further emulsifiers are such as PEG glyceryl 4 oleates, PEG glyceryl stearate with 3-1000 ethylene glycol units.

Lipophilic emulsifiers may also be used, e.g. Partial esters of polyols such as glycerol monoesters, of sugar esters such as sucrose distearate, sorbitan sesquioleate or pentaerythritol.

Anionic surfactants are, for example, lipophilic radicals having anionic groups such as carboxylate, sulfate, sulfonate or phosphate groups. These include alkyl sulfates in the form of alkali, ammonium or alkanolammonium salts such as sodium laureth sulfate.

Cationic surfactants are in particular quaternary ammonium compounds or else esterquats.

Preferred cosmetic esters and ethers are, for example, steareth-2, steareth-21, cetearyl octanoate, isopropyl myristate, neopentyl glycol dicaprylate, stearyl ether.

As cosmetic oils, known oils such as mineral oils, vegetable oils, silicone oils can be used. Particularly preferred are silicone oils such as dimethicones, cyclomethicones.

The clay minerals include smectites, phyllosilicates, kaolin, talc, bentonite, montmorillonite. They are used in particular in a cosmetic mask, optionally together with a zeolite.

Polyhydric alcohols are e.g. Glycerol, propylene glycols; Monohydric alcohols are e.g. Ethanol, propanol, i-propanol.

The skin-lightening cosmetic composition may be in the form of application as a cream, gel, lotion, serum, mask, make-up or foundation, especially as day cream, night cream, cleansing gel, serum and mask. Preferred masks are face and décolleté masks.

Another object of the invention is a cosmetic, non-therapeutic method for skin whitening, in which at least a first series of cosmetic compositions of a set is applied to the skin surface and applied at intervals of 10 - 16 hours a second series of cosmetic compositions, wherein the The first and the second series comprise as application forms a cleansing gel, a serum and a cream, which in addition to cosmetic adjuvants contain the combinatorial unit consisting of ground white jade stone with a mean particle size D ₅₀ of 5-10 μm, arbutin, a lotus flower extract, a Kumquat fruit extract and dimethylmethoxy chroman palmitate.

The method is preferred in that the cream of the first series is a day cream that additionally contains UV filters, and the cream of the second series is a night cream that does not contain UV filters.

Preferably, in the morning after application of the cleaning gel, e.g. A serum is applied to the complete facial area, neck and possibly shoulder and décolleté area, a contact time of 1 to 15 minutes and subsequent washing of these areas with water and allowed to act for 1 to 15 minutes, preferably 8 to 15 minutes. Then the day cream is applied.

Preferably in the evening, ie after about 10 to 14 hours, the cleansing gel, the serum and the night cream are applied in the same order.

The process is carried out for at least one week, preferably for 1 to 6 weeks, especially for 1 to 4 weeks.

In a further embodiment of the method, the application forms additionally comprise a mask which is applied 1 to 3 times, preferably 2 to 3 times a week, and which comprises a combinatorial unit consisting of ground white jade stone with a mean particle size D ₅₀ of 5 - 10 μm, arbutin, a lotus flower extract, a kumquat fruit extract and dimethylmethoxy chroman palmitate. Also included are conventional auxiliaries for a cosmetic mask, such as cosmetic esters, water, silicates, zeolite, etc.

Another object of the invention is a cosmetic set for lightening the skin, comprising as application forms a day cream, a night cream, a cleansing gel, a serum and optionally a mask, each application form containing cosmetic excipients and the combinatorial unit and the combinatorial unit 0.01 to 0.5% by weight of a milled white jade stone having a particle size D ₅₀ of 5 to 10 μm, 0.1 to 1% by weight, arbutin, 0.5 to 1.5% by weight of an extract of white Lotus flowers, 0.1 to 2.5 wt .-% of an extract of Kumquatfrüchte and 0.01 to 0.1 wt .-% dimethylmethoxy chroman palmitate, each based on the total weight of the application form.

Preferred is a set which additionally contains a mask which, like the other components of the set, comprises the combinatorial unit.

The invention is illustrated by examples. All figures are in percent by weight, based on the total weight of the particular form of application.

example 1 cleaning gel

Phase A water until 100 % Glycerine 6.0 Sodium Laureth Sulfate 10.0 Carbomer 0.5 Phase B Triethanolamine 0.5 Phase C Nelumbo Nucifera Flower Extract 0.5 arbutin 0.1 Dimethylmethoxy chroman palmitate 0.01 Citrus Japonica Fruit Extract 0.5 Jade (Powder) 0.01 preservative 0.8

The components of phases A and C are mixed separately at 15-25 ° C with stirring. Subsequently, the phases B and C are successively added with stirring to phase A and homogenized.

Example 2 serum

water until 100 % Glycerine 3.0 Carbomer 0.8 triethanolamine 0.8 ethanol 10.0 preservative 0.5 Perfume 0.5 Nelumbo Nucifera Flower Extract 1.5 arbutin 0.8 Dimethylmethoxy chroman palmitate 0.08 Citrus Japonica Fruit Extract 2.3 Jade (Powder) 0.08

The ingredients are mixed together in the order given with stirring at ambient temperature (15-25 ° C). At the end, the combinatorial unit is added as a premix.

Example 3 Day cream with SPF 15

Phase A water until 100 % Glycerine 2.0 Carbomer 0.8 Phase B Dimethicone 2.0 Shea butter 3.0 Until Ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb ^® S) 1.5 Ethylhexyl methoxycinnamate 7.5 Steareth-21 2.0 Phase C Triethanolamine 0.8 Phase D Nelumbo Nucifera Flower Extract 1.5 arbutin 0.8 Dimethylmethoxy chroman palmitate 0.01 Citrus Japonica Fruit Extract 2.0 Jade (Powder) 0.1 Hyaluronic Acid 0.2 Chamomilla Recutia Flower Extract 0.5 preservative 0.8 Perfume 0.5

The phases A and B are heated to 70-75 ° C with stirring, combined and homogenized for about 10 minutes. Phase C is added and the mixture homogenized for about 5 minutes. After cooling to about 40 ° C, the separately prepared at ambient temperature phase D is added with stirring and then cooled to 30 ° C.

Example 3a Day cream II

The procedure is as in Example 3. The content of arbutin is 0.5%, of dimethylmethoxy chroman palmitate 0.02% and lotus flower extract 1.2%.

Example 4 night cream

Phase A water until 100 % Glycerine 3.0 Carbomer 1.0 Phase B Steareth-21 2.0 Steareth-2 1.7 Dimethicone 5.0 Phase C Triethanolamine 1.0 Phase D Nelumbo Nucifera Flower Extract 0.5 arbutin 0.9 Dimethylmethoxy chroman palmitate 0.01 Citrus Japonica Fruit Extract 2.0 Jade (Powder) 0.5 preservative 0.8 Chamomilla Recutia Flower Extract 1.0 Perfume 0.5

The preparation is carried out as in Example 3.

Example 5 mask

Phase A water until 100 % Zeolite 1.0 Glycerine 3.0 bentonite 3.0 kaolin 35.0 Talc 3.0 Phase B Propylene glycol hydroxystearates 2.0 Isopropyl lanolates 3.0 preservative 1.0 Phase C Nelumbo Nucifera Flower Extract 1.0 arbutin 0.5 Dimethylmethoxy chroman palmitate 0.05 Citrus Japonica Fruit Extract 0.5 Jade (Powder) 0.1 Chamomilla Recutia Flower Extract 0.5 Camellia Sinensis Leaf Extract 0.1 Perfume 1.0

The constituents of phase A are mixed at 70 ° C. with stirring and homogenized about 20, whereby the uniform pigment distribution is tested. The ingredients of phase B are heated to 70 ° C with stirring, and phases A and B are combined, homogenizing for at least 15 minutes. After cooling to 40-45 ° C, the phase with the premix of the combinatorial unit is added with stirring and it is homogenized again.

Example 6 method

From 12 subjects (female, age 22-43 years) with the skin type "Tan" or "Matt" ( Chardon et al., Int. J. Cosm. Scien. 13, 191-208, 1991 ) (corresponds to the skin type "Mediterranean dark, Asian" in another classification), the cleaning gel was applied according to Example 1 in the morning on the facial skin by intensive, rubbing pressure for 2 minutes. Then the facial skin was rinsed with water.

The serum according to Example 2 was uniformly massaged into the facial skin and allowed to act for 10 minutes. Thereafter, the day cream according to Example 3 was evenly distributed on the facial skin.

Part of the subjects were also exposed to direct sunlight during the day, but no longer than a total of 2 hours. After 12 hours, the cleansing gel and the serum were applied in the same manner as in the morning and then the night cream according to Example 4.

The procedure was repeated daily over a period of 21 days. On days 5, 10 and 14, a mask according to example 5 was applied between the application in the morning and in the evening on the face. The exposure time of the mask was 10 minutes. Afterwards, the mask was rinsed with water.

The evaluation took place on days 0, 7, 14 and 21 by experienced testers using color charts. The color charts showed 10 shades of brown in increments of 10% change with each shade of brown. The results are shown in Table 1. Table 1 Measurement after [days] Brightening [%] Proportion of subjects [%] 3 20 65 7 40-50 75 30 25 14 60-70 83 50 17 21 90 25 70-80 58 60 17 42 90 17 80 33 60 42 50 8th

The re-measurement after 42 days after the start of the test was carried out without a treatment was performed after the 21st day.

The results show a very rapid effectiveness of the treatment, since already after 3 days visible whitening results were recognizable and in the majority of the subjects after 7 days already up to 50% brightening were found.

The sustainability of the lightening shows the result after 21 days, according to which the decrease in lightening without treatment is only used with great reluctance and the majority of the subjects are still in the 60-80% range.

No undesirable color changes or skin irritations were detected.

Example 7 comparison

A comparison experiment also with 12 subjects (female, age 25-44 years) with the skin type "Tan" to "Matt" was carried out in a similar manner as in Example 6. Exception: The respective cosmetic application forms cleansing gel, serum, creams and mask contained the combinatorial unit without the ingredient kumquat fruit extract, which was replaced in the overall compositions by a higher proportion of water.

In a shortened evaluation after 3, 7, 21 and 42 days, the results according to Table 2 were achieved. Table 2 Measurement after [days] Brightening [%] Proportion of subjects [%] 3 0 100 7 10 25 21 40 25 30 58 10 17 42 30 25 10 66 0 9

The results show that the faster effectiveness of the compositions of the invention is not achieved and also the longer-lasting effect only in a small part of the subjects and at a lower level.

Claims (8)

1. A skin-lightening cosmetic composition comprising cosmetic auxiliaries and a combinatory unit consisting of 0.01 to 0.5 % by weight of ground white jade stone with an average particle size D₅₀ of 5-10 µm;
   arbutin in the range from 0.1 to 1.0 % by weight; a lotus flower extract in the range from 0.5 to 1.5 % by weight, obtained at 12-30°C using a polyvalent alcohol;
   a kumquat fruit extract in the range from 0.1 to 2.5 % by weight, obtained at 12-35°C from the fruits including the skin using a polyvalent alcohol; and Dimethylmethoxy Chroman Palmitate in the range from 0.01 to 0.1 % by weight, each relative to the total weight of the cosmetic composition.
2. The composition according to claim 1, characterized in that, as cosmetic auxiliaries, it comprises sun filters, antioxidants, hyaluronic acid, gel-forming agents, emulsifiers, cosmetic ethers, cosmetic esters, oils, clay minerals and mixtures thereof.
3. The composition according to Claim 1 or 2, characterized in that it is provided as a mask, cream, serum or gel.
4. A cosmetic, non-therapeutic method for skin-lightening, characterized in that daily at least one first series of cosmetic compositions of a set are applied to the skin surface and 10-16 hours later a second series of cosmetic compositions are applied, wherein the first and the second series comprise, as forms of application, a cleansing gel, a serum and a cream, each of which contains a combinatory unit according to Claim 1 or 2 and cosmetic auxiliaries.
5. The method according to Claim 4, characterized in that the cream of the first series is a day cream which additionally contains UV filters, and the cream of the second series is a night cream which does not contain any UV filters.
6. The method according to any one of Claims 4 to 5, characterized in that it is carried out for at least one week, preferably for 1-4 weeks.
7. The method according to Claim 4, characterized in that the forms of application additionally comprise a mask which is applied 1 to 3 times per week and which comprises a combinatory unit according to Claim 1 or 2.
8. A cosmetic set for lightening the skin, comprising, as forms of application, a day cream, a night cream, a cleansing gel, a serum and optionally a mask, wherein each form of application contains cosmetic auxiliaries and a combinatory unit according to Claim 1.